headers/private/kernel/arch/m68k/arch_kernel.h

   1 /*
   2 ** Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
   3 ** Distributed under the terms of the NewOS License.
   4 */
   5 #ifndef _KERNEL_ARCH_M68K_KERNEL_H
   6 #define _KERNEL_ARCH_M68K_KERNEL_H
   7
   8 #include <arch/cpu.h>
   9
  10 // memory layout
  11 #define KERNEL_BASE 0x80000000
  12 #define KERNEL_SIZE 0x80000000
  13 #define KERNEL_TOP  (KERNEL_BASE + (KERNEL_SIZE - 1))
  14
  15 /*
  16 ** User space layout is a little special:
  17 ** The user space does not completely cover the space not covered by the kernel.
  18 ** This is accomplished by starting user space at 1Mb and running to 64kb short of kernel space.
  19 ** The lower 1Mb reserved spot makes it easy to find null pointer references and guarantees a
  20 ** region wont be placed there. The 64kb region assures a user space thread cannot pass
  21 ** a buffer into the kernel as part of a syscall that would cross into kernel space.
  22 */
  23 #define USER_BASE     0x100000
  24 #define USER_BASE_ANY USER_BASE
  25 #define USER_SIZE     (0x80000000 - (0x10000 + 0x100000))
  26 #define USER_TOP      (USER_BASE + (USER_SIZE - 1))
  27
  28 #define KERNEL_USER_DATA_BASE   0x60000000
  29 #define USER_STACK_REGION              0x70000000
  30 #define USER_STACK_REGION_SIZE ((USER_TOP - USER_STACK_REGION) + 1)
  31
  32 #endif  /* _KERNEL_ARCH_M68K_KERNEL_H */